Our universe seems strangely ''biophilic,'' or hospitable to life. Is this happenstance, providence, or coincidence? According to cosmologist Martin Rees, the answer depends on the answer to another question, the one posed by Einstein's famous remark: ''What interests me most is whether God could have made the world differently.'' This highly engaging book explores the fascinating consequences of the answer being ''yes.'' Rees explores the notion that our universe is just a part of a vast ''multiverse,'' or ensemble of universes, in which most of the other universes are lifeless. What we call the laws of nature would then be no more than local bylaws, imposed in the aftermath of our own Big Bang. In this scenario, our cosmic habitat would be a special, possibly unique universe where the prevailing laws of physics allowed life to emerge.

Rees begins by exploring the nature of our solar system and examining a range of related issues such as whether our universe is or isn't infinite. He asks, for example: How likely is life? How credible is the Big Bang theory? Rees then peers into the long-range cosmic future before tracing the causal chain backward to the beginning. He concludes by trying to untangle the paradoxical notion that our entire universe, stretching 10 billion light-years in all directions, emerged from an infinitesimal speck.

As Rees argues, we may already have intimations of other universes. But the fate of the multiverse concept depends on the still-unknown bedrock nature of space and time on scales a trillion trillion times smaller than atoms, in the realm governed by the quantum physics of gravity. Expanding our comprehension of the cosmos, Our Cosmic Habitat will be read and enjoyed by all those--scientists and nonscientists alike--who are as fascinated by the universe we inhabit as is the author himself.

If God created the universe and there is no other intelligent life out there, or any life at all, then he's a wasteful idiot. Just imagine the vastness of space - are you telling me he needed that much room just to make us?

If the universe came about due to natural forces and there is no other intelligent life out there, or any life at all, then the universe is a stupid, idiotic place. Just imagine that vastness again - are you telling me that either the universe needed that much space just to produce us, or that in all that vastness it could not come up with anything else?

I'm prepared for either event and I don't really care if there is intelligent life "out there" or not, but I know at least one thing - the absence of life/intelligence outside of earth would be solid proof of either God's or the unvierse's inadequacy.


A fine starter but nothing more   February 3, 2004
 5 out of 6 found this review helpful

Martin Rees masterpiece remains for sure "Just Six Numbers". In a few pages, he has been able to track the most intriguing mysteries of physics, by explaining how small changes in "just six numbers" could have prevented us from being...
The idea behing this book is to cover quite broadly all the aspects of modern cosmology. The question which permeates the entire book is "is our existence just an accident, or do we exist because we had to (i.e. the laws of physics imply our existence)"? This is currently THE question in cosmology. After having tracked and measured the most significant quantities that set the laws of our universe, we have started to question "why" those numbers have the values that allows for our existence.
Of course there is no answer in the book, but what is disappointing is that the book just looks like a collection of short stories and information already seen in other books.
Whoever has already read books on cosmology, quantum mechanics and relativity will find just a repetition of short summaries, with a little characterisation by the author.
The good point is that this book can surely be a good starter for neophytes.


Deep Mysteries of the Cosmos Simply Told   December 23, 2003
 5 out of 6 found this review helpful

Martin Rees, Astronomer Royal of Great Britain, wonderfully tells everything about cosmology in this concise book. The reader is lead to a quick tour from Big Bang to biospheres, from the beginning to the end of the universe, and from the micro-world to the cosmos. Yet the description is not superficial but very deep.

Among many of mysteries we learn from this book, let me mention only a few big ones. (1) Dark matter: This prevails over visible matter in constituting the total energy of the universe. It is the No. 1 problem in astronomy today, and ranks high as a physics problem, too. (2) Vacuum energy: This is the origin of the accelerating expansion of the universe. Its nature is a challenge to theorists; it holds important clues to the early universe and the nature of space. (3) Other universes: Our universe may be just one of them. While seeming to be in the province of metaphysics rather than physics, these already lie within the proper purview of science.

The author says that the phrases often used in popular books, "final theory" and "theory of everything," are very misleading and that some of nature's complexity may never be explained and understood. These words just made the scales fall from my eyes. I strongly recommend this book to laypersons interested in astronomy, cosmology, problems at the boundary between science and philosophy, and the deep mysteries of nature.


Local bylaws and the multiverse   September 3, 2003
The first nine chapters of this rather small book give us an excellent summary of our actual scientific and speculative cosmological knowledge.
In the last two chapters the author explains why he believes that the history of our universe is just an episode (a particular Big Bang) in an infinite multiverse (see also Lee Smolin's 'The Life of the Cosmos').

This clearly written (a bonus) book tackles also other important items, like the risk for an encounter with a devastating asteroid, the impact of a unified theory on science, or the still more demote cosmic status of humanity - we are even not made of the dominant stuff in our universe.

A very interesting read. Not to be missed.